High-Q2 elastic ed scattering and QCD predictions.

In the framework of pertubative QCD it is argued that in the elastic edscattering at Q ∼ few (GeV/c) the light-cone-frame helicity-flip amplitudes could not be omitted. The obtained B A ratio of Rosenbluth structure functions is shown to be in a good agreement with experimental data. The high Q behavior of T20 is discussed. In a recent paper, Brodsky and Hiller [1] have made a general analysis of the e.m. properties of spin-one systems prceeding from the gauge theory. They have mentioned that in the analysis of high energy elastic ed-cross-sections at least two momentum scales must be distinguished. The first one is given by the QCD scale ΛQCD ≈ 200MeV/c and determines the perturbative QCD regime. In particular, according to arguments of Ref.[2], this scale controls a high Q suppression of the lightcone-frame helicity-flip matrix elements of the deuteron e.m. current